light, heat, thermodynamics, wave motion, sound, optics & oscillations - Category wise Question and Answer Practice Test with Solutions

Question : 16 [PSC (Pre) 2016]

Assertion (A):
In the visible spectrum of light, red light is more energetic than green light.
Reason (R):
The wavelength of red light is more than that of green light.
Code

a) (A) is true, but (R) is false

b) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

c) Both (A) and (R) are true and (R) is the correct explanation of (A)

d) (A) is false, but (R) is true

Question : 17

The sound from an open pipe is more pleasant than the sound from a closed pipe. This is because :

a) there are more overtone combinations in an open pipe than in a closed one

b) sound is heard from both the sides of an open pipe

c) it is very easy to operate an open pipe

d) the length of the open pipe is shorter

Question : 18 [NDA]

‘Pitch’ is a characteristic of sound that depends upon its

a) fequency

b) intensity

c) quality

d) None of these

Question : 19

A ray of light travels from medium I to medium II. The figure given shows the variation of sin of angles of incidence (sin i) in medium I with sin of angle of refraction (sin r) in medium II.

1. Speed of light in medium I > Speed of light in medium II.
2. Speed of light in medium I < Speed of light in medium II.
3. Light travels from denser medium to rarer medium.

a) 1 and 3

b) 1 only

c) 2 only

d) 2 and 3

Question : 20 [IAS (Pre) 1994]

A glass bottle containing water tightly corked breaks when it is kep in freeze, because

a) The volume of water decreases on freezing

b) The volume of water increases on freezing

c) Bottle shrinks on freezing

d) Glass is the bad conductor of heat